a 230 kg steel crate is being pushed along a cement floor. the force of friction is 480 n to the left and the applied force is 1860 n to the right. what is the normal force?
a.) 480 n down
b.) 480 n up
c.) 2300 n down
d.) 2300 n up

The correct answer is

D.) 2300 N up

In fact, the normal force is the reaction force exerted by the surface on the object, perpendicular to the surface itself, equal and opposite to the weight of the object.

Therfore, the magnitude of the normal force is equal to the weight of the object:

And since the weight is downward, the normal force is upward.